1. Field of the Invention
The invention relates to method and apparatus for reclaiming tobacco from reject cigarettes.
2. Brief Description of the Prior Art
In the manufacture of cigarettes it is the usual practice to reclaim tobacco from cigarettes failing to meet quality control standards. Conventionally, reclaiming has been effected by longitudinally slitting the cigarette paper enclosing the tobacco. When reclaiming tobacco from filter cigarettes, filters are removed prior to slitting. Disclosures of the prior art methods may be found, for example, in U.S. Pat. Nos. 1,956,925 and 3,224,451.
U.S. Pat. No. 3,577,999 describes an alternative prior art technique in which reject cigarettes pass through a mechanical beater. In this device, the tobacco columns are passed through a zone where they are struck by paddles which expel the tobacco from the ends of the paper tube.
Another prior art technique is described in Canadian Pat. No. 764,741. This patent teaches one to soften the glue seam with water and steam and then to open the seam by physical engagement such as with rollers, to remove the tobacco. The water-treated cigarettes may also be placed on a vibrating screen to separate the tobacco with hot air blown through the screen to dry the tobacco as it is being separated from the paper.
In German Pat. No. 894,226 non-filter cigarettes are moistened along the glue seam and then conveyed through a steam filled chamber, apparently at atmospheric pressures, to apparently permeate the paper and/or cigarette with water vapor. The treated cigarette is then thrown against a vibrating plate, preferably heated, to break open the cigarette wrapper and release the tobacco. This method was apparently directed toward cigarettes containing tobacco wrapped under tension.
Contrary to the prior art approaches, which generally attempt to minimize moistening of the tobacco and/or entail physically striking the cigarette, the present process of the invention requires moisture saturation of the cigarette paper wrapper, followed by the impact of steam under pressure on the wet cigarette. It is believed that an increased vapor pressure within the cigarette body occurs, caused by vaporizing of moisture which has permeated the paper wrapper. If the temperature of the cigarette body is high enough to melt the glue seam, the increased internal pressure will force open the weakened glue seam. If the glue seam does not open because it is insufficiently weakened, the tobacco rod is expelled from the open end or ends of the wrapper upon impact of the steam. This action may be a result of an increased vapor pressure within the cigarette body, caused by vaporization of moisture carried through the paper wrapper. The advantage of the process of the invention resides in the reclaimed tobacco, which unexpectedly exhibits minimal reduction in tobacco particle size. The long strands of the tobacco are generally reclaimed intact. Generally, the moisture content of the cigarettes is increased by about 10% by weight, consequently there is a need for subsequent drying steps. In addition, if the reject cigarette includes a filter component, the filter structure may be separated intact. This is particularly advantageous in reclaiming tobacco from cigarettes having multiple or pocket filters in which a portion of a filter is comprised of a granular material, such as charcoal. Such granular material would be admixed with the tobacco during reclaiming if the integrity of the filter structure was destroyed. This is, of course, an undesirable contamination of the tobacco. The invention, however, is broadly applicable to the reclaiming of tobacco from all types of cigarettes, whether filtered or unfiltered.